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Biomedical subjects

M Turina

Publications and source records attributed to M Turina.

At least 379 records · Page 21Linked to original sources
PubMed1988

Performance characteristics of a disposable ventricle assist device.

A disposable ventricle assist device (VAD) including atrium, ventricle and trileaflet valves (all polyurethane) can be driven either a) by its original self adjusting drive unit (ABIOMED BVS 5000) or b) by a standard intra-aortic balloon pump console (DATASCOPE). Maximum flow in vitro was 4.3 l/min with the original drive console versus 9.2 l/min for activation with the intra-aortic balloon pump console. Performance characteristics of the VAD were evaluated in 11 bovine experiments. In vivo left ventricular assist for up to 24 hours with VAD and either original drive console or standard intra-aortic balloon pump console showed superior flow on activation with the intra-aortic balloon pump console (5.3 +/- 1.7 l/min) versus original drive console (3.5 +/- 0.5 l/min). After 6 hours of assist (before any transfusions) there was no significant difference in classic parameters for evaluation of blood trauma such as plasma hemoglobin production, LDH production and platelet depletion. We conclude that VAD is extremely simple to use. Activation by an intra-aortic balloon pump console enables significant increase of VAD-output without detectable increase of blood trauma. Successful weaning of VAD activated with standard intra-aortic balloon pump console was possible in a first clinical application.

Aortic Valve Insufficiency↗
PubMed1988

Myocardial structure in patients with exercise-induced ischemia.

Myocardial structure of left ventricular segments with recurrent myocardial ischemia was evaluated by morphometry and compared with that of segments with normal blood supply in 15 patients with exercise-induced myocardial ischemia. Left ventricular high-fidelity pressure measurements and simultaneous biplane angiocardiography were performed in patients at rest and during supine bicycle exercise. Left ventricular transmural biopsy samples were obtained during open heart surgery in a normally contracting region and in a region with exercise-induced de novo wall motion abnormalities. Transmural and endocardial and epicardial left ventricular muscle fiber diameter and interstitial nonmuscular tissue were determined by morphometry. Eight patients were restudied 8 months after successful bypass grafting. Heart rate and left ventricular end-diastolic pressure increased significantly preoperatively and postoperatively during exercise. However, left ventricular end-diastolic pressure was significantly higher preoperatively (33 mm Hg) during exercise than postoperatively (19 mm Hg; p less than .01). Left ventricular ejection fraction dropped significantly during exercise (63% vs 54%; p less than .001) before surgery but remained unchanged (64% vs 66%; NS) after revascularization. Regional axis shortening of the normokinetic region increased slightly during exercise pre- and postoperatively, but decreased in the hypokinetic region from 42% at rest to 25% during exercise (p less than .001) before surgery and from 47% at rest to 41% during exercise (p less than .05) after revascularization. Transmural muscle fiber diameter (normal less than or equal to 23 microns) was significantly larger in regions with exercise-induced ischemia (29.3 microns, p less than .025) than in normally contracting regions (27.3 microns). Interstitial nonmuscular tissue (normal less than or equal to 10%) was significantly increased in regions with exercise-induced wall motion abnormalities (19.8%) compared with normally contracting regions (15.5%; p less than .05). In the endocardial half of left ventricular segments with recurrent myocardial ischemia interstitial tissue was significantly increased (23.7%; p less than .01) compared with that in the epicardial half of the same segment (17.5%). It is concluded that structural alterations of the myocardium (muscle fiber hypertrophy and increased interstitial nonmuscular tissue) develop especially in the endocardial layers of the transiently ischemic myocardium with normal function at rest.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiocardiography↗
PubMed1988

Long-term outlook after atrial correction of transposition of great arteries.

Late results were reviewed in 220 survivors after atrial correction of transposition of the great arteries who were operated between 1964 and 1985. Senning's procedure and its various modifications have been used; all patients who survived 30 days after correction were included in this analysis. Average follow-up for the whole group was 10.3 years; 113 patients were observed for 10 years, 26 patients for 15 years, and 8 patients for 20 years. The actuarial survival rate for the whole group was 89% at 10 years, 87% at 15 years, 82% at 20 years. It was higher in simple than in complex transposition (92% versus 84% at 10 years). Sudden deaths (8 patients) and late heart failure (6 patients) were the principal causes of death, predominantly in the complex transposition group (10/13 deaths). Late survival was more common in the latter part of the study, with 95% of patients operated on after 1978 surviving 9 years as opposed to 84% of patients operated on earlier. Late reoperation was necessary in 18 patients (8%), with 12 reoperations occurring within 2 years after correction. Cumulative reoperation rate reached 11.7% after 10 years. Reoperations were more common in complex than in simple transposition (14% versus 6%, p less than 0.05). Late arrhythmias can occur after atrial correction, and the cumulative incidence of pacemaker implantations was 8% at 10 years. Most of the survivors are functionally free of symptoms (83% of the simple and 75% of the complex transposition group). Significant tricuspid valve incompetence was encountered in only three patients, with two valve reconstructions being possible. In summary, long-term outlook for survivors of atrial correction for transposition of the great arteries remains encouraging, although complex transposition does seem to engender more late problems. Atrial correction is still warranted in simple transposition, but close cardiological surveillance is necessary.

Actuarial Analysis↗
PubMed1987

[Perioperative antibiotic prophylaxis in heart and vascular surgery. A prospective randomized comparative study with cefazolin and ceftriaxone].

Two different forms of cephalosporin prophylaxis were investigated in a prospective randomized comparative study: a one-day cefazoline prophylaxis (Kefzol 0.5 g every six hours) and a single dose of ceftriaxone (Rocephin 2 g). A total of 541 patients were included in the study over 10 months: 272 in the cefazoline (CFZ) group and 269 in the ceftriaxone (CRO) group. The patients were checked postoperatively for an infection. The total rate of infections was 4.7%; 4.6% in the CFZ group and 4.8% in the CRO group. A wound infection occurred in 1.1% of the cases, in 0.4% of the CFZ group and in 1.8% of the CRO group. Septicemia was diagnosed in 1.5% of the operated patients; in 1.2% of the patients treated with CFZ and in 1.8% of the patients treated with CRO. 1.3% of the patients developed pneumonia, 1.8% in the CFZ and 0.8% in the CRO group. Only one patient had a urinary tract infection (CFZ group). Furthermore, two double infections occurred in the CFZ group. A double infection was observed only once in the CRO group. Fever of unclear etiology developed in 3.6% of the patients in both groups. There was no statistically significant difference with regard to the rate of infection between the two groups. A single administration of ceftriaxone prophylaxis is accordingly just as effective as a one-day cefazoline prophylaxis. Despite reduction of the antibiotic application, the rate of infection has not risen in the last five years. The single application is advantageous compared to longer-term applications.

Cardiac Surgical Procedures↗
PubMed1987

Antimicrobial prophylaxis in cardiovascular surgery.

In the past five years three prospective randomized studies compared five different prophylactic antimicrobial regimens in major cardiovascular surgery. In 1980/81 a 4 d cefazolin (CFZ) prophylaxis (16 X 0.5 g) was compared with a 2 d cefuroxime (CFX) administration (4 X 1.5 g). Of the 566 patients who entered the study 281 received CFZ and 285 were given CFX. In 1982/83 a 2 d CFX prophylaxis (4 X 1.5 g) was compared with a two shot ceftriaxone (CRO) prophylaxis (2 g i.v., + 1 g 24 h later). Of the 512 patients enrolled 258 received CFX and 254 CRO. In 1984/85 a 1 d CFZ prophylaxis (4 X 0.5 g) was compared with a single shot prophylaxis of CRO (1 X 2 g). Of the 541 patients who entered the study 272 received CFZ and 269 CRO. All patients of age 16 y or older who were undergoing open heart surgery (n = 1384) and surgery of the major arteries (n = 235) were eligible for trial entry with the following exceptions: patients with preoperative infections, those who had received an antibiotic within 48 h of operation, and any with known allergies to cephalosporins or who had suffered an anaphylactic reaction to any penicillin. The patients were allocated to one of the two treatments by means of a randomized code, stratified for cardiac and major vascular operations. The first dosis was always given prior to surgery at the beginning of anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1987

Does exercise-induced myocardial ischaemia cause enhanced platelet activation and fibrin formation in patients with stable angina and severe coronary artery disease?

In this study, betathromboglobulin (BTG) and fibrinopeptide A (FPA) in peripheral venous blood were measured in 20 patients with stable angina pectoris before and immediately after exercise-induced myocardial ischaemia; in 5 of the 20 patients stable angina was associated with typical peripheral artery disease. A total of 10 patients with angiographically documented peripheral artery disease without angina and 10 normal volunteers were taken as control groups. BTG and FPA in the 15 patients with stable angina before exercise were 41 +/- 14 ng ml-1 and 2.3 +/- 0.9 ng ml-1 and were not statistically different from the values in normal controls; after exercise-induced myocardial ischaemia no significant increase occurred in these patients. Conversely, in the 5 patients with stable angina associated with peripheral artery disease BTG and FPA before exercise were 61 +/- 10 ng ml-1 and 3.5 +/- 0.8 ng ml-1 and increased to 114 +/- 14 ng ml-1 (P less than 0.001) and 4.1 +/- 0.5 ng ml-1 (P less than 0.01): These results were similar to those found in the 10 patients with isolated peripheral artery disease. We conclude that BTG and FPA in peripheral venous blood in patients with stable angina are not elevated either at rest or after exercise-induced myocardial ischaemia. Elevated values of BTG and FPA in patients with stable angina may reflect a major interaction between blood and atherosclerotic vessel wall, suggesting the presence of associated atherosclerotic lesions in peripheral artery disease.

Angina Pectoris↗
PubMed1987

Early results after mitral valvuloplasty for pure mitral regurgitation.

In this study we present the results of 105 consecutive patients with pure mitral regurgitation who underwent surgical treatment. In all patients mitral regurgitation was associated with mitral valve prolapse: 54 patients underwent mitral valvuloplasty and 51 patients mitral valve replacement. Clinical assessment and echocardiography were used as follow-up criteria at one year after surgery. After mitral valvuloplasty, NYHA decreased from 2.7 +/- 0.8 to 1.1 +/- 0.7 (P less than 0.01) and workload capacity increased from 65 +/- 28% to 96 +/- 25% (P less than 0.001); left endsystolic atrial dimension and enddiastolic dimension decreased from 6.2 +/- 0.8 to 4.8 +/- 1.2 cm (P less than 0.001) and from 7.2 +/- 1.3 to 5.9 +/- 0.8 cm (P less than 0.01); ventricular contraction fraction did not change significantly. After mitral valve replacement, clinical and echocardiographic improvement was significant but less remarkable than after valvuloplasty; ventricular contraction fraction fell from 39 +/- 7% to 29 +/- 8% in contrast to patients undergoing mitral valvuloplasty in whom no significant change occurred. Complications were rare in both groups though only a minority of patients undergoing mitral valvuloplasty received anticoagulants. We conclude that mitral valvuloplasty in patients with pure mitral regurgitation when compared with the patients after mitral valve replacement.

Echocardiography↗
PubMed1986

[Significance of the bicuspid aortic valve in the incidence of aortic valve defects in adults].

In 388 patients with severe isolated aortic valve disease bicuspid aortic valves were found in 45% of patients with aortic stenosis and 24% of patients with aortic regurgitation. There was a history of rheumatic fever in 16% and of endocarditis in 7% of these patients. In a group of 110 patients with severe combined aortic and mitral valve disease, 50% had a history of rheumatic fever and bicuspid valves were found in only 12% of the cases. Severe aortic valve disease based on bicuspid valves was most frequently found in the age group 50-69 years. Bicuspid aortic valve is today the most frequent cause of isolated aortic valve disease; it is more common in aortic stenosis but also occurs in aortic regurgitation.

Adolescent↗